High efficiency alkaline earth metal thiogallate-based phosphors

1. A strontium calcium thiogallate phosphor doped with divalent europium, and having the following formula:

Sr 1-x Ca x Ga 2 S 4 :yEu 2+ .zGa 2 S 3 ,

where x is a value such that both Sr and Ca are present and is greater than or equal to 0.0001, y is a value defining sufficient Eu 2+ to provide luminescent emission, and z is greater than 0.07 up to 0.2 based on the mole amount of Sr 1-x Ca x Ga 2 S 4 .

2. The phosphor of claim 1 , wherein z is 0.08 to 0.2.

3. The phosphor of claim 1 , wherein z is 0.09 to 0.2.

4. The phosphor of claim 1 , wherein y is 0.001 to 0.1 based on the mole amount of Sr 1-x Ca x Ga 2 S 4 .

5. The phosphor of claim 4 , wherein y is 0.01 to 0.08

6. The phosphor of claim 4 , wherein y is 0.01 to 0.04.

7. The phosphor of claim 1 , wherein the phosphor has an emission peak of 535 nm to 560 nm.

8. The phosphor of claim 7 , wherein the emission peak has a bandwidth of 50 nm or less under excitation with an emission source at 440 nm±40 nm.

9. The phosphor of claim 1 , wherein the phosphor has an emission peak of 536 nm to 560 nm.

10. The phosphor of claim 1 , wherein the phosphor has an emission peak of 537 nm to 560 nm.

11. The phosphor of claim 1 , wherein the phosphor has an emission peak of 538 nm to 560 nm.

12. The phosphor of claim 1 , wherein the phosphor has an emission peak of 539 nm to 560 nm.

13. The phosphor of claim 1 , wherein the phosphor has an emission peak of 540 nm to 560 nm.

14. The phosphor of claim 1 , wherein the phosphor has an emission peak of 541 nm to 560 nm.

15. The phosphor of claim 1 , wherein the phosphor is made up of particles with primary particles that are in the size range 2–4 microns.